子类中扩展property

考虑如下的代码，它定义了一个property：

class Person:
    def __init__(self, name):
        self.name = name

    # Getter function
    @property
    def name(self):
        return self._name

    # Setter function
    @name.setter
    def name(self, value):
        if not isinstance(value, str):
            raise TypeError('Expected a string')
        self._name = value

    # Deleter function
    @name.deleter
    def name(self):
        raise AttributeError("Can't delete attribute")
下面是一个示例类，它继承自Person并扩展了 name 属性的功能：

class SubPerson(Person):
    @property
    def name(self):
        print('Getting name')
        return super().name

    @name.setter
    def name(self, value):
        print('Setting name to', value)
        super(SubPerson, SubPerson).name.__set__(self, value)

    @name.deleter
    def name(self):
        print('Deleting name')
        super(SubPerson, SubPerson).name.__delete__(self)
接下来使用这个新类：

>>> s = SubPerson('Guido')
Setting name to Guido
>>> s.name
Getting name
'Guido'
>>> s.name = 'Larry'
Setting name to Larry
>>> s.name = 42
Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "example.py", line 16, in name
        raise TypeError('Expected a string')
TypeError: Expected a string
>>>
如果你仅仅只想扩展property的某一个方法，那么可以像下面这样写：

class SubPerson(Person):
    @Person.name.getter
    def name(self):
        print('Getting name')
        return super().name
或者，你只想修改setter方法，就这么写：

class SubPerson(Person):
    @Person.name.setter
    def name(self, value):
        print('Setting name to', value)
        super(SubPerson, SubPerson).name.__set__(self, value